Physical quantities and measurements

What is Science?

The knowledge gained through observations and experimentations.

What is Physics?

Physics is the branch of science that studies matter, energy, and their interactions.

What are physical quantities?

All measurable quantities which are characteristics of every object.

What are the basic characteristics of physical quantities?

(i) Numerical magnitude (ii) Unit in which it is measured.

What are base quantities?

Physical quantities that form the foundation for other physical quantities.

What are derived quantities?

Quantities that can be described in terms of base quantities.

Why is a standard unit needed for measurement?

To compare a quantity with some standard quantity for correct measurement.

What is the International System of Units (SI)?

A worldwide system of measurements adopted in 1960.

What are base units?

Units that describe the base quantities.

What are derived units?

Units used to measure derived quantities, derived from base units.

What are some standard prefixes used for multiples and submultiples?

Prefixes like Kilo (k), Mega (M), Giga (G) for large quantities and Milli (m), Micro (µ), Nano (n) for small quantities.

How are numbers expressed in Scientific Notation?

By expressing them as a power of ten multiplied by a number between 1 and 10.

What is a Meter Rule?

An instrument used to measure length with a least count of 1mm.

Why is a micrometer screw gauge more accurate than a vernier caliper?

Because it can measure up to one hundredth part of a millimeter while a vernier caliper can measure only up to one tenth.

What is an electronic balance?

An instrument used to measure the mass of a body electronically.

What is the function of a measuring tape?

It is used to measure length in meters and centimeters.